The "G" Fund is invested in very short-term U.S. Treasury securities guaranteed by the federal government. These are unique government securities not available to the general public and are backed by the full faith and credit of the U.S. Government. The G Fund was the initial fund established when the TSP began operations on April 1, 1987. There is no risk of loss of principal. As set forth by law, the interest rate is equal to the average rate of return on outstanding Treasury securities with four or more years to maturity. There is no ticker symbol for the G Fund.
The "F" Fund is invested in BlackRock's U.S. Debt Index Fund and tracks the Bloomberg U.S. Aggregate Bond Index. The F Fund opened to federal employees in January 1988. This index represents a diversified group of U.S. government, corporate, and mortgage-related securities. For tracking purposes, the closest comparable is the iShares Core U.S. Aggregate Bond ETF (ticker: AGG). Through the G and F Funds, TSP participants with low risk tolerance can avoid the stock market entirely.
The "C" Fund is invested in BlackRock's Equity Index Fund, a portfolio of stocks replicating the performance of the Standard & Poor's 500 Index, meaning it invests in very large-cap U.S. stocks. The C Fund opened to employees in January 1988. It behaves similarly to S&P 500 index funds. For tracking purposes, we use the S&P 500 Large Cap Index (ticker: $SPX).
The "S" Fund is invested in BlackRock's Extended Market Index Fund, a portfolio of stocks tracking the Dow Jones U.S. Completion Total Stock Market Index. The S Fund opened to employees in May 2001. It covers the non-S&P 500 stocks in the U.S. market; combined with the C Fund, it covers nearly the entire U.S. stock market. For tracking purposes, we use the Dow Jones U.S. Completion TSM Index (ticker: $DWCPF).
The "I" Fund is invested in BlackRock's EAFE Index Fund, a portfolio designed to track the performance of the MSCI EAFE Index, which represents large companies in 21 countries across Europe, Australia, and the Far East. The I Fund opened to employees in May 2001. For tracking purposes, we use the iShares MSCI EAFE Index Fund (ticker: EFA).
Knowing the funds is just the start.
Since 2005, ThriftTrading subscribers have averaged +10.15% per year, outperforming the buy-and-hold strategy by +2.63%. We send IFT alerts directly to you so you always know when to move and where to allocate.
View Subscription Options →All TSP funds are trust funds regulated by the Office of the Comptroller of the Currency, not the Securities and Exchange Commission. Employees may choose any combination of the individual funds (allocations must be expressed as whole percentages) and may change their allocation for future pay periods at any time. If no selection is made, the default is 100% into the G Fund. As all funds except the G Fund carry a potential risk of loss of principal, an employee is required to acknowledge this risk before investing in those funds.
Participants may also change the allocation percentage of their existing fund balances through Interfund Transfers (IFTs). Since May 2008, participants are limited to two unrestricted transfers per calendar month; all subsequent transfers must be into the G Fund only.
The TSP's Lifecycle (L) Funds are target-date funds that automatically invest in a mix of the five core TSP funds based on your expected retirement date. Each L Fund starts with a more aggressive allocation and gradually shifts to a more conservative mix as the target date approaches. This rebalancing happens automatically. No action is required from the participant.
The current L Fund lineup is:
| Fund | For Those Retiring Around | Risk Profile |
|---|---|---|
| L Income | Already retired or withdrawing | Most conservative — heavy G and F Fund allocation |
| L 2025 | 2021 – 2027 | Very conservative |
| L 2030 | 2028 – 2032 | Moderately conservative |
| L 2035 | 2033 – 2037 | Moderate |
| L 2040 | 2038 – 2042 | Moderately aggressive |
| L 2045 | 2043 – 2047 | Aggressive |
| L 2050 | 2048 – 2052 | More aggressive |
| L 2055 | 2053 – 2057 | Very aggressive |
| L 2060 | 2058 – 2062 | Very aggressive |
| L 2065 | 2063 and beyond | Most aggressive — heavy C, S, and I Fund allocation |
When a fund reaches its target date, it is merged into the L Income Fund and participants' assets are automatically transferred. The L Funds are rebalanced daily to maintain their target allocations.
In June 2022, the TSP introduced the Mutual Fund Window, giving participants access to a broader range of investment options beyond the five core funds and Lifecycle funds. Through the window, participants can invest in thousands of mutual funds from external providers.
However, the Mutual Fund Window comes with important restrictions and costs: a one-time enrollment fee, a quarterly maintenance fee, and per-trade transaction fees apply. A minimum balance requirement must be met, and participants may only invest up to 25% of their TSP balance in the window at any time. Additionally, funds in the Mutual Fund Window are not eligible for the same low-expense-ratio advantages that make the core TSP funds exceptional.